1611664644 has 12 divisors (see below), whose sum is σ = 3760550864. Its totient is φ = 537221544.

The previous prime is 1611664643. The next prime is 1611664657. The reversal of 1611664644 is 4464661161.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (1611664643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67152682 + ... + 67152705.

Almost surely, 2^1611664644 is an apocalyptic number.

It is an amenable number.

1611664644 is an abundant number, since it is smaller than the sum of its proper divisors (2148886220).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1611664644 is a wasteful number, since it uses less digits than its factorization.

1611664644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134305394 (or 134305392 counting only the distinct ones).

The product of its digits is 82944, while the sum is 39.

The square root of 1611664644 is about 40145.5432644771. The cubic root of 1611664644 is about 1172.4425181137.

The spelling of 1611664644 in words is "one billion, six hundred eleven million, six hundred sixty-four thousand, six hundred forty-four".